Cultivation in industrially relevant conditions has a strong influence on biological properties and performances of Nannochloropsis gaditana genetically modified strains

Microalgae are promising feedstocks for the production of biofuels thanks to their high biomass yield and the lack of competition with food crops for arable land. Algal industrial exploitation, however, still needs to address several technological challenges to reach energetic and economic sustainability. Genetic improvement of microalgae strains is seminal to fully exploit the potential of these organisms. In this work, we investigated how key environmental parameters affected productivity of a promising genetically modified algal strain cultivated in industrially relevant conditions. We observed that intensive growth conditions strongly influenced algae biology as evidenced by molecular and functional analyses. We also showed that specific operational conditions significantly affected performances, enhancing or reducing the advantages of the strains genetic modification, such as the chlorophyll content per cell and the abundance of photosynthetic apparatus components. This work demonstrates the presence of a strong influence of cultivation environment on the phenotype of improved strains, suggesting that operational parameters have a seminal influence on algae performances and must be taken into full account during strains development efforts.